At the top right corner, click the gear icon and select Billing from the dropdown menu.

In your “Transaction history”, select Detailed from the drop-down menu.

In the Description column, you'll see a line item for your payment. Here are the different descriptions you might see:

Automatic payment scheduled: A payment will happen in the next few days. This status shows for accounts on automatic payments with a bank account listed as the primary payment method. Once the payment is complete, it'll show as Automatic payment.

In progress: A cost, payment, or adjustment is underway. Once the payment has been completed, it'll show as Payment or Automatic payment. It might take a couple minutes until this line item shows up on the Transaction history page after a manual payment has been made.

Payment: A payment you've initiated has been applied to your account.

Automatic payment: An automatic payment has been applied to your account.

At the top right corner, click the gear icon and select Billing from the dropdown menu.

In your “Transaction history”, you'll see your "Current balance" with a negative or positive balance.

Here's what each means:

Negative numbers show account credit that'll be used for future advertising costs. If you're on automatic payments, you'll see a negative account balance only if you've decided to make a payment for more than your previous balance.

Positive numbers show the amount that you owe for ad activity you've already accrued. Sometimes a positive balance can appear in brackets in your AdWords Express account. If you're on automatic payments, your balance will usually be positive unless you've made a payment for more than your previous balance. It's not possible to have a positive balance if you're on manual payments.